Truck



l5, 1943 3 Sheets-Sheet l Emme E79 94?, L. A. LEHRMAN TRUCK Filed Dec.

Fume Vi, w47., L. A. LEHRMAN TRUCK Filed Dec. l5, 1945 3 Sheets-Sheet 2HVVENTOR. a@ qe%wwoww Jun@ E?? i947. L.. A. LEHRMAN TRUCK Filed Dec. 13,1943 3 4Sheets-Sheet 3 O jZ 12@ je @of INVENTOR. jnm

l Patented June 17, 1947 TRUCK Leo A. Lehman, Chicago, Ill., assignor toAmerican Steel Foundries, Chicago, Ill., a corporation of New JerseyApplication December 13, 1943, Serial No. 514,033

(Cl. lofi-197) 28 Claims. 1

My invention relates to railway car trucks and more particularly to atruck incorporating a ride control device for frictionally controllingoscillations of the bolster supporting spring group.

The general object of my invention is to provide a ride control truckincorporating a quick wheel change feature whereby the bolster may beremoved from the top of the bolster opening in assembled relationshipwith the friction shoes while a portion at least of the bolstersupporting spring group remains in assembled relationship with the sideframe.

The present invention is an improvement on the generic designillustrated and described in David M. Light Patent 2,392,599, issued inthe United States Patent Ofce January 8, 1946, and a specific object ofthe present invention is to design a truck of this type wherein aplurality of friction shoes are provided at opposite sides of thebolster in wedge engagement therewith and in frictional engagement withthe side frame columns, said shoes being actuated by means of a platemember extending transversely of the bolster and housed therein, saidmember being resiliently urged into engagement with the friction shoes.

In one embodiment of the present invention,

Y the friction shoe actuator or pressure plate member is connected bymeans of a bolt and nut assembly extending through the bottom Wall ofthe bolster to a spring adjustably compressed against said bottom wall,and in another illustrated embodiment of the present invention, thefriction shoe actuator affords a seat for its associated spring which isconnected to the bottom Wall of the bolster by means of a bolt and nutassembly extending through a central opening in the actuator.

My invention comprehends a bolster of novel form having a pocket in eachside thereof defined by inboard and outboard walls or Webs and anintervening rear wall with an opening therethrough for the reception ofthe adjacent end of the associated friction shoe actuator, a ledge beingintegrally formed with each of said inboard and outboard walls at oneside of said opening and presenting a wedge surface sloping toward theouter extremity of the pocket.

My invention also comprehends a friction shoe of novel form having amain friction Wall integrally formed with spaced ledges presenting Wedgesurfaces. A rib extends between the ledges at the upper extremitiesthereof, said rib being Still another object of my invention is todesign a novel friction shoe actuator or pressure plate having atopposite ends and on the bottom thereof spaced abutment surfaces forcooperation with the associated friction shoes under normal operatingconditions, said actuator also comprising at opposite ends thereof andon the top thereof wedge surfaces for cooperation with means on theassociated friction shoes to maintain the latter in assembledrelationship with the bolster during assembly and disassembly of theside frame therewith.

In the drawings:

Figure 1 is a fragmentary side elevation of a railway car truckembodying my invention, portions of the structure being illustrated insection along the longitudinal vertical plane bisecting the side frame.

Figure 2 is a fragmentary top view of the structure shown in Figure 1with the side frame columns illustrated in section.

Figures 3 to 5 illustratey in detail the novel bolster shown in Figures1 and 2-, Figure 3 being a fragmentary side elevation, Figure 4 being afragmentary top plan view thereof, and Figure 5 being a fragmentarysectional View taken in the plane indicated by the line 5-5 of Figure 3.

Figures 6 to 8 inclusive illustrate in detail the novel friction shoeshown in Figures 1 and 2, Figure 6 being a top plan view thereof, Figure'7 being a side elevation thereof, and Figure 8 being a rear elevationtaken from the actuator engaging face thereof.

Figures 9 and 10 illustrate a modicationof my invention, Figure 9 beinga fragmentary sectional view comparable to Figure 1, and Figure 10 beinga sectional view of the bolster and associated friction meansillustrating the manner in which the friction means is retained inassembled relationship with the bolster during assembly and disassemblythereof with the side frame.

Figures 1l and 12 illustrate in detail the friction shoe actuator shownin Figures 9 and 10, Figure 1l being a top plan view of the actuator,and Figure 12 being a side elevation thereof.

Describing my invention in detail and referring first to the embodimentthereof illustrated in Figures 1 to 8 inclusive, the side framecomprises a tension member 2 and a compression member 4 merging adjacenteach end of the frame with a column 6 dening therewith a bolster opening8 and the window opening III, the bolster opening 8 having a widenedupper portion I2 to permit insertion and removal of the bolstertherethrough as hereinafter described. The tension member 2 is ofwell-known form with the central boxsection portion thereof having a topweb I6 widened and formed with an upstanding flange I8 at each of theinboard and outboard sides thereofl to dene a spring seat 20 on the topweb I6 for a group of bolster supporting springs diagrammat-l icallyindicated at 22, 22, which are seated at 24 (Figure 1) against thebottom wall 26 of the bolster generally designated 28.

The bolster 28 is of box-like form with the before-mentioned bottom wall26 and the top wall 38, as well as the spaced side walls 32, 32, andformed in each side of the :bolster is a pocket 34 defined by theinboard and outboard walls 36 and 38 and the rear wall or web 48extending therebetween substantially parallel to the side Walls 32, 32of the bolster. The web 48 is formed with an opening 42 for thereception of the associated end of the friction shoe actuator orpressure plate as hereinafter described, and at the inboard and outboardsides of the opening 42 are formed the diagonal walls 44 and 46 mergingwith the rear wall 48 and with the respective inboard and outboard walls36 and 38, each diagonal wall 44 and 46 sloping downwardly toward theadjacent col` umn 6 and presenting a wedge surface for comv plementaryengagement at 48 with the associated friction shoe generally designated58.

One of the friction shoes 58 is shownV in detail in Figures 6 to 8inclusive, said shoe comprising a main friction wall 52 frictionallyengaged at 54 with the adjacent column-mounted wear plate 56 (Figures 1and 2). Integrally formed with the main friction wall 52 of the frictionshoe 58 are the spaced triangular ledges 58 and 68 presenting on theirlower surfaces crowned wedge faces for complementary engagement as at 48with the inboard and outboard bolster Walls 44 and 46 in the mannerabove described. Extending between the ledges 58 and 68 is a rib 62affording an abutment for a wedge face on the associated friction shoeactuator during assembly and disassembly of the side frame and bolsteras hereinafter described. A lug 64 projects from the main friction Wall52 beneath the rib 62, said lug being reinforced by the spaced gussets66, 66 and presenting a top crowned abutment surface 68 for engagementas at 18 with an equalizer, sometimes called a friction shoe actuator orpressure plate generally designated 12, said plate having the centralopening 14 therethrough for the reception of a bolt 16, the head ofwhich abuts the plate 12 as at 18 and is restrained against rotationalmovement with respect thereto by means of the inboard and outboard lugs88 and 82 formed on the top of the plate 12.

A spring 84 is sleevedrover the bolt 16 and is seated at 86 against thebottom wall 26 of the bolster, the lower end of the spring being seatedagainst a, spring plate 88 which is adjustably compressed against thespring 84 by means of ai nut 98.

On the top of the friction shoe actuator or pressure plate 12 adjacentopposite ends thereof are formed the wedge surfaces 92, 92slopingdownwardly toward the opening 14, said wedge surfaces 92, 92being adapted for cooperation with the ribs 62, 62 of the friction shoes58, 58 during assembly of the truck. This is accomplished by driving awedge between the plate 12 and the boss 94 formed on the top of thebottom wall 26 of the bolster', thus urging the plate 12 upward, wherebythe Wedge surfaces 92, 92 engage the ribs 62, 62 of the respectivefriction shoes, thereby urging the latter inwardly into the Dockets 34,34 of the bolster. l

Under these conditions, it will be understood that the bolster may beentered at the top of the bolster opening 8 and may be lowered thereinuntil suflicient clearance is afforded to permit entry of 4 the bolt 16.The wedge is then removed from between the boss 94 and the plate 12 andthe bolt 'I6 is lowered into engagement with the plate 12 and thebolster. Thereafter the spring 84 is al plied to the lower end of thebolt and is adjusted to the desired compression'by means of the nut 98.The bolster is then elevated to the desired height within the bolsteropening to permit assembly of the bolster supporting springs 22, 22.

It will be understood that during a quick wheel change, the bolster maybe elevated in the bolster opening and removed from the widened upperportion thereof after the inboard springs 22, 22 have been removed fromthe side frame to afford clearance for the spring 84 and the lower endof the bolt 16, and it may be noted that after thc spring 84 has beencompressed to urge the friction shoes 58, 58 into engagement with thecolumns, the Ipressure on the shoes may be relieved by driving a wedgebetween the boss 94 and the plate 12, thus facilitating elevation of thebolster within the bolster opening.

As will be clearly understood from a consideration'of Figures 2 and 3,each side of the bolster is provided with the inboard andoutboard columnguide lugs 96 and 98 for cooperation with the inboard and outboardsurfaces of the columns 6, 6, thus affording an interlock .between theside frame and the bolster, the outboard lugs 98, 98 being of less depththan the widened upper por- -tion I2 of the bolster opening to permitinsertion of the bolster at the top of the bolster opening and theremoval of the bolster therefrom during assembly and disassembly of thetruck as heretofore described.

Referring now to the modification of `my invention illustrated inFigures 9 to 12 inclusive, the side frame generally designated |82 issubstantially identical with that shown in Figures 1 anfl 2, said frameincluding the spaced columns |84, |84 and the intervening bolsteropening |88 with the widened upper portion |88. Seated on the side frame|82 are the bolster supporting springs diagrammatically indicated at II8, I I8 and affording support for the bolster generally designated II2,said bolster (being generally similar to that of the previous embodimentand comprising; at each side thereof a pocket I I4 for the reception ofa friction shoe I I6, said shoe comprising a ledge I I8 at each sidethereof incomplementary wedge engagement as at |28 `with the diagonalbolster wall |22 formed within the pocket I I4 at each of the inboardand outboard sides thereof. The rear extremity of the pocket is definedby the rear wall |24 having a central opening |26 therethrough for thereception of the friction shoe actuator or pressure plate |28.

The pressure plate or equalizer |28 isillustrated in detail in Figures11 and 12 and comprises at opposite ends thereof the wedge surfaces |38,|38 converging downwardly toward the central opening |32 through theplate, the Wedge surfaces |38, |38 being in complementary engagement asat |34 with the lugs I 36, |38` formed on the friction shoes ||6, |I6. Aspring |38 is seated on the top of the plate |28, the upper end of saidspring being seated against a spring plate |48 which is adjustablycompressed against the spring by means of a nut |42 threaded on theupper end of the bolt |44 which extends through the opening |32 in theplate |28 and is interlocked at its lower extremity at |46 with thebottom wall of the bolster.

Figure 10 illustrates the manner in which the friction shoes areretained within the pockets I I4,

I4 during assembly of the bolster and side frame, the pressure plate |28having at opposite ends thereof the top wedge surfaces |48, |4'8 forvcomplementary engagement as at |50, |50 (Figure with the ribs |52, |52on the friction shoes. The plate |28 is urged upwardly into wedgeengagement with the shoes by means of an assembly wedge block |54inserted between the plate 28 and a boss |56 formed on the bottom wallof the bolster. It will be understood that the friction shoes I I6, I6in the arrangement illustrated in Figure 10 are urged inwardly into thebolster pockets, thus permitting the bolster and shoes to be inserted asa unit into the widened upper portion |08 of the bolster opening |06 andlowered onto the springs ||0, ||0. Thereafter, the wedge block |54 maybe removed and the bolt |44 may be applied by means of a tool insertedbetween the outboard springs ||0, ||0. The spring |38 may then be placedin position and adjustably compressed by means of the nut |42. In theevent that it is desired to elevate the bolster to remove one of thesprings ||0, ||0, the nut |42 may be loosened or, if desired, a wedgemay be inserted between the boss |56 and the plate |28.

It will be understood that the arrangement illustrated in Figures 9 and10 is substantially identical with that illustrated in Figures 1 and 2except for the fact that the actuating plate |28 is in wedge engagementwith the shoes at |34, |34, and the spring l 38 is connected to thebolster and to the plate 28 in the reverse of the manner illustrated inFigures 1 and 2, whereby the nut |42 is disposed at the top of thebolster opening where it may be readily adjusted without disassemblingthe truck.

It is to be understood that I do not wish to be limited by the exactmodifications of the dev ice shown which are merely by way ofillustration and not limitation as various and other forms of the devicewill, of course, be apparent to those skilled in the art withoutdeparting from the spirit of the invention or the scope of the claims.

I claim:

1. In a railway car truck, a side frame comprising tension andcompression members and spaced columns defining therewith a bolsteropening with a widened upper portion, a. spring group on said tensionmember in said bolster opening, a bolster supported by said group, saidbolster having pockets in opposite sides thereof, each" pocketcomprising spaced inboard and outboard wedge surfaces therein slopingtoward the adjacent column, a friction shoe in each pocket engaging theWedge surfaces therein and frictionally engaging the adjacent column, aplate member extending between the spaced-surfaces in each pocket andbearing against said shoes, said plate member being housed within thebolster, resilient-l means operatively associated with said bolster andsaid member for urging the latter into engagement with said shoes, andinboard and outboard lugs on said bolster cooperating with said columnsto afford an interlock with said frame, the outboard lugs being of lessdepth than the widened upper portion of said bolster opening, wherebysaid bolster may be elevated therein and removed therefrom.

2. In a railway car truck, a side frame comprising tension andcompression members and spaced columns defining therewith a bolsteropening, a spring-group on said tension member in said opening, abolster supported by said group, said bolster having pockets in oppositesides thereof, each pocket comprising spaced inboard and outboard wedgesurfaces sloping downwardly toward the adjacent column, a friction shoein each pocket engaging the spaced wedge surfaces therein andfrictionally engaging the adjacent column, a plate member extendingbetween the spaced surfaces in said pockets and bearing against saidshoes, said plate member being housed within the bolster, resilientmeans compressed against the bottom wall of said bolster, and a bolt andnut assembly connected to the lower end of said resilient means and tosaid plate member for transmitting reaction of said resilient meansthereto.

3. In a railway car truck, a side frame comprising tension andcompression members and spacdicolumns defining therewith a bolsteropeningafgpring group on said tension member in said opening, a bolstersupported by said group. said bolster having pockets in opposite sidesthereof. each pocket comprising spaced inboard and outboard wedgesurfaces sloping downwardly toward the adjacent column, a friction shoein each pocket engaging the spaced wedge surfaces therein andfrietionally engaging the adjacent column, a plate member extendingbetween the spaced surfaces in said pockets and bearing against saidshoes, said plate member being housed within the bolster, resilientmeans seated on the upper surface of said plate member, and a bolt andnut assembly connected to the upper end of said resilient means and tothe bottom wall of said bolster.

4. In a railway car truck, a side frame comprising tension andcompression members and spaced columns defining therewith a bolsteropening, a spring group on said tension member in said opening, abolster supported by said group, said bolster having pockets in oppositesides thereof, each pocket comprising spaced inboard and outboard wedgesurfaces sloping downwardly toward the adjacent column, a friction shoein each pocket engaging the spaced wedge surfaces therein andfrictionally engaging the adjacent column, a plate member extendingbetween the spaced surfaces in said pockets and bearing against saidshoes, said plate member being housed within the bolster, and resilientmeans operatively associated with said bolster and said member forurging the latter into engagement with said shoes.

5. In a railway car truck, a side frame com-v prising spaced columns andan intervening bolster opening, resilient means on said frame in saidopening, a bolster supported from said resilient means and comprising atop wall, said bolster comprising Wedge surfaces at opposite sidesthereof sloping downwardly toward respective co1- umns, friction shoesin wedge engagement with respective of said surfaces and in frictionalengagement with friction means on respective columns, an actuator housedwithin the bolster beneath said top wall-and extending transverselythereof, and resilient means independent of said first-mentionedresilient means for urging said actuator into engagement with saidshoes, whereby the latter` are urged into engagement with said wedgesurfaces and said friction means.

6. In a railway car truck, a side frame comprising spaced columns and anintervening bolster opening, resilient means on said frame in saidopening, a bolster comprising a top wall and a bottom wall spacedtherefrom, said bottom wall being supported from said resilient means,friction shoes in wedge engagement with wedge means on said bolster andin frictional engagement with friction means on said columns, an`

actuator housed within the'bolster between said walls and extendingtransversely thereof, resilient means under compression, and a bolt andnut assembly operatively connected to said lastmentioned resilient meansand to said actuator fortransmitting reaction of said last-mentionedresilient means thereto.

7. In a railway car truck, a side frame comprising spaced columns and anintervening bolster opening, resilient means on said frame in saidopening, a bolster supported on said resilient means and comprising topand bottom' Walls, friction shoes engaging wedge means on said bolsterat opposite sides thereof, and an actuator' assembly partially housedwithin said bolster and operatively associated with said shoes forurging the same into engagement with said wedge means and with theassociated columns, said assembly comprising a rigid member disposedbetween said walls, and resilient means bearing against said rigidmember for urging it into engagement with said shoes.

8. In a railway car truck, a side frame comprising spaced columns and anintervening 'bol` ster opening, resilient means on said frame in saidopening, a bolster supported from said resilient means and comprising atop wall, friction shoes in wedge engagement with wedge means on saidbolster and in frictional engagement with friction means on saidcolumns, an actuator housed within the bolster and extendingtransversely thereof andunderlying said top wall, and resilient meansfor urging said actuator into engagemcnt with said shoes, whereby'thelatter are urged into engagement with said wedge and friction means.

9. In a railway car truck, a side frame comprising spaced columns and anintervening bol`- ster opening, a spring group on said frame in saidopening, a bolster member supported on said group and comprising a topwall, friction shoes in wedge engagement with said bolster and infrictional engagement with respective columns, 'a pressure member housedin said bolster, extending transversely thereof beneath said wall, andbearing against said shoes, resilient means under compression seatedagainst one of said members, and a'bolt and nut assembly connected tosaid resilient means and to the other of said members.

10. In a railway car truck, a side frame comprising sr aced columns andan intervening bolster opening, resilient means on said frame in saidopening, a bolster supported on said resilient means, friction shoesengaging wedge means on said bolster at opposite sides thereof, and anactuator assembly partially housed within said bolster and operativelyassociated with said shoes for urging the same into engagement with saidwedge means and with the associated columns, said assembly comprising aat rigid member housed within the bolster and bearing at each endthereof against abutment means on the shoe associated with onecolumn,'said abutment means ing an abutment face on its upper surface.,all of said faces being crowned.

12. Inv a friction shoe actuator member for a railway car truck, a platehaving means centrally thereof for connection to an associated element,abutment means on one side of said plate for cooperation undercertainconditions with associated friction shoes, and wedge faces on the otherside of said plate converging toward said firstnmentioned means* andformed and arranged for coqperation under other conditions with saidshoes.

13. In a friction shoe, a member having a main friction wall, spacedledges projecting from one side of said wall and presenting wedge facesdiagonal with respect thereto, an abutment rib extending between saidledges and spaced from said wall, and a lug projecting from said side ofsaid wall beneath the level of said rib, said lug having a-top surfaceformed and arranged for abutment with an associated actuator.

14. In a railway car truck, a side frame comprising spaced columns andan intervening bolster opening, a box-section bolster resilientlysupported from said frame in said opening, wedge means at opposite sidesof said bolster, friction shoes engaging respective wedge means andfrictionally engaging adjacent columns, and means urging said shoes intoengagement with said wedge means and columns comprising an equalizerdisposed between the topand bottom walls of said bolster and engagingabutment means on said shoes.

15. A friction shoe and bolster assembly comprising a box-sectionbolster with pockets in opposite sides thereof and wedge surfaces insaid pockets, friction shoes engaging respective surfaces, and means formaintaining said shoes within said pockets comprising a rigid memberhoused between the top and bottom walls of the bolster and having wedgesurfaces engaging abutment surfaces of said shoes.

16. A friction shoe and bolster assembly comprising a bolster withpockets in opposite sides thereof, wedge surfaces on said bolster withinsaid pockets, friction shoes in said pockets engaging respectivesurfaces, and means for maintaining said shoes within said pocketscomprising a member housed within the bolster and-bearing againstrespective shoes and a wedge block wedged between said member and a wallof said bolster.

17. In a railway car truck, a side frame member, a bolster memberlspring-supported therefrom, a portion-of one of said members extendingbetween spaced friction surfaces of the other member, friction shoesengaging wedge means on said portion and frictionally engagingrespective surfaces, actuating means for said shoes comprising a member`housed within said portion and engaged with said shoes, and resilientmeans carried by said portion for urging said last-mentioned member intoengagement with said shoes.

18. In a, railway car truck, a side frame comprising spaced columns, abox-section bolster spring-supported from said frame between saidcolumns, friction shoes engaging respective columns 4and wedge means onsaid bolster, actuating means for said shoes comprising a member housedbetween the top and bottom walls of the bolster in engagement with saidshoes, and resilient means operatively connected to said member forurging the same into said engagement.

19. In a railway car truck, a side frame comprising spaced columns, abolster spring-supported therebetween, friction shoes engagingrespective columns and engaging Wedge means movable with said bolster,actuating means for said shoes comprising spaced spring abutmentmembers, one 'of which is anchored to the bolster and the other of whichis engaged with said shoes,

and resilient means compressed between said members for urging saidother member into engagement with said shoes.

20. In a railway car truck, a side frame comprising spaced columns, abolster spring-supported therebetween, friction shoes engagingrespective columns and engaging wedge means movable with said bolster,actuating means for said shoes comprising spaced spring abutmentmembers, one of which is anchored to the bolster and the other of whichis engaged with said shoes, and resilient means compressed between saidmembers for urging said other member into engagement with said shoes,said other member being housed within the bolster and being partiallyhoused within each shoe.

21. In a railway car truck, a side frame comprising spaced columns. abox-section bolster spring-supported therebetween and comprising top andbottom walls, friction shoes engaging respective columns, wedge meansvertically movable with said bolster and in complementary wedgeengagement with said shoes, actuating means for said shoes comprisingspaced interconnected abutment members, one of which is disposed betweensaid walls in engagement with said shoes, and resilient means compressedbetween one of said walls and the other of said members for urging thefirst-mentioned member into engagement with said shoes.

22. In a railway car truck, a side frame comprising spaced columns, abox-section bolster 'spring-supported therebetween and comprising topand bottom walls, friction shoes engaging respective columns, wedgemeans vertically movable with said bolster and in complementary wedgeengagement with said shoes, and actuating means for said shoescomprising spaced interconnected abutment members, one of which isdisposed between said walls in engagement with said shoes. and resilientmeans compressed between one of said walls and the other of said membersfor urging the first-mentioned member into engagement with said shoes,said first-mentioned member being housed at each end thereof within oneof said shoes.

23. In a railway car truck, a side frame member, a bolster memberspring-supported therefrom, vone of said members having a portionextending between spaced friction surfaces on the other of said members,said portion having wedge means adjacent respective surfaces, frictionshoes each cooperating with one of said surfaces and the adjacent wedgemeans, and actuating means for said shoes comprising spaced plates, oneof which is anchored to said portion and the other of which engages saidshoes, and resilient means compressed between said plates for urgingsaid other plate into engagement with said shoes.

24. In a railway car truck, a. side frame member, a bolster memberspring-supported therefrom, one of said members having a portionextending between spaced friction surfaces on the other of said members,said portion having top and bottom walls and wedge means adjacentrespective surfaces, friction shoes each cooperating with one of saidsurfaces and the'adjacent wedge means, and actuating means for saidshoes comprising a pair of spaced interconnected plates,

one of which engages abutment means on said shoes at a point betweensaid walls, and resilient means compressed between the other plate and awall of said bolster for urging the first-mentioned plate against saidabutment means.

25. In a railway car truck, a side .frame member, a bolster memberspring-supported therefrom, one of said members having a portionextending between spaced friction surfaces on the other of said members,said portion having wedge means adjacent respective surfaces, frictionshoes each cooperating with one of said surfaces and the adjacent wedgemeans, and actuating means for said shoes comprising-'a pair of spacedinterconnected plates, one of which engages abutment means on saidshoes, and resilient means compressed between the other plate and a wallof said -bolster for urging thefirst-mentioned plate against saidabutment means, said first-mentioned plate having its ends housed withinsaid shoes and being housed for its entire length within said portion.

26. In a railway car truck, a side frame comprising spaced columns andan intervening bolster opening, a box-section bolster resilientlysupported from said frame in said opening, wedge means at opposite sidesof said bolster, friction shoes engaging respective wedge means andfrictionally engaging adjacent columns, and means urging said shoes intoengagement with said wedge means and columns comprising an equalizerdisposed between the top and bottom walls of said bolster and engagingabutment means on said shoes, said equalizer transmitting verticalforces lfrom said bolster to said shoes.

27. In a railway car truck, a side frame comprising spaced columns andan intervening bolster opening, a box-section bolster resiligntlysupported from said frame in said opening, wedge means at opposite sidesof said bolster, friction shoes enga-ging respective wedge means andfrictionally engaging adjacent columns, and means urging said shoes intoengagement with said wedge means and columns comprising an equalizerresiliently mounted in said bolster and bearing upon4 REFERENCES CITEDThe following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 2,053,991 Goodwin Sept. 8. 19362,118,006 Couch May 17, 1938 2,257,109 Davidson Sept. 30, 1941 2,306,395Cottrell Dec. 29, 1942- 2,346.860 Mohl Apr. 18, 1944 2,362,989 CottrellNov. 21, 1944 2,392,597 Lehrman Jan. 8, 1946 2,392,599 Light Jan. 8,1946

